Programmable logic controller



FIG. 1 is a front view of the controller incorporating my new design;

FIG. 2 is a top view;

FIG. 3 is a rear view;

FIG. 4 is a right side view;

FIG. 5 is a left side view;

FIG. 6 is a bottom view; and,

FIG. 7 is a perspective view of the controller of FIG. 1 viewed from the lower right hand corner. 

The ornamental design for a programmable logic controller, as shown and described. 